The rates of respiration of immature Fugu obscurus were measured in freshwater under conditions of different water temperature and DO.The results show that the variations of water temperature and DO can both cause the relative changes of respiratory rate.The water temperature become a major factor affecting the rates of respiration when DO saturation≥65%,and water temperature ranges between 10～32℃.The higher the temperature,the faster breathing is.The rates of respiration change from 47times·min -1 to 177times·min -1 with temperature rising from 10℃ to 32℃.The variations of the respiratory rates are also corresponding to the changes of water DO.The rate of respiration change from 120times·min -1 to 177timese·min -1 at water temperature 22℃,and from 125·min -1 to 180·min -1 at 24℃ respectively. When the amount of water DO declines from 8～2.1mg·min -1 L -1 .Inaddition,the movement of immature Fugu obscurus appear obviously weak,slowly moving,or motionlessly staying at the bottom of aquarium.Then a pre-suffocative reaction occurs when the DO decreases continuously to less than 2.1mg·L -1 at the temperature 22℃ and 24℃.
